Abstract :Introduction: Lichen planus, is a chronic autoimmune, mucocutaneous disease affecting the oral mucosa besides the skin, genital mucosa, scalp and nails.The exact etiology of oral lichen planus is unknown. The disease most commonly affects middle-aged females. Oral lichen planus usually presents as white striations (Wickham's striae), white papules, white plaque, atrophic , ulcerative, erosive or as blisters. There is a well established correlation between oral lichen planus and liver disease. Opinion amongst researchers vary on terminology of lichen planus and lichenoid drug reaction . Recent literature reported association between lichen planus and thyroid disease. Aim: The main aim of this study is to evaluate the association between oral lichen planus and thyroid disease and its prevalence amongst patients visiting our dental institute. Materials and methods: 67 case sheets of patients, diagnosed with oral lichen planus between June 2019 and March-2020 were retrieved from the electronic database . Collected data were entered into the Excel sheet and was analysed using SPSS analysis. Results: Results showed a positive association between oral lichen planus and thyroid disease, mainly hypothyroidism (7.46%). Females were more affected than males (53.7%).The erosive variant of oral lichen planus was more prevalent among the study population (44.7%). There was a positive correlation between predominant clinical variety of Lichen planus and site involved. The positive correlation between hypothroid state and lichen planus is also reported. Conclusion: In conclusion, our study establishes an association between oral lichen planus and a coexisting thyroid disorder mainly hypothyroidism .